Owners of other Mazda vehicles such as the Mazda2, Mazda3, Mazda5, CX-3, CX-5, CX-7, CX-9, and the MX-5 Miata may also find these DIY instructions to be helpful.

The compatible replacement light bulb part numbers are as follows: Rear Turn Signal # 7440A (also 7440NA or WY21W), Rear Side Marker # 2825 and Reverse # 7440 (or W21W).

The only tool needed to access and replace the tail light bulbs is a small flathead screwdriver or a pop rivet removal tool.

(The brake lights are LED bulbs that should last the life time of the vehicle.)

If you need to replace a bulb in the passenger side housing, lift out the plastic storage tray.

Set the tray aside in a safe place.

Move to the top of the black plastic trim piece that covers the outer edge of the trunk.

Pry out the center of the pop rivet fastener before pulling out the base.

Warning - If you live in a very cold climate, I recommend removing all of the fasteners on the plastic panel and lifting it out of the trunk to avoid having it crack or break. Plastic can become very brittle in colder weather.

If you live in a warm climate, very gently pull back the top of the plastic trim panel to access the last pop rivet that secures the carpet liner to the rear of the trunk.

Don't pull too hard on the plastic piece to avoid having it crack.

Pry up the center of the pop rivet before removing the base of it.

Gently pull back the grey carpeted trunk liner to reveal the two bulb sockets.

The larger grey socket contains the rear turn signal bulb. The smaller black plastic socket contains the rear side marker.

Pull the old light bulb straight out of the socket and push in a new amber colored number 7440A (also known as the 7440NA or WY21W).

Rotate the smaller black plastic side marker bulb socket 1/4 turn counterclockwise before pulling it straight out of the housing.

Pull the old light bulb straight out of the socket.

Push in a new miniature wedge base number 2825 bulb straight in to the socket.

Re-insert the socket in to the housing and rotate it 1/4 turn clockwise to secure it in place.

Re-insert the pop rivet to hold the carpet in place and push in the center part to secure the fastener.

Push the plastic trim piece back in to place over the rear edge of the trunk opening.

Lower the plastic storage tray back in to place.

Open the trunk lid and locate the three black plastic pop rivets along the outer edge of the carpeted liner panel.

Set the three pop rivets aside in a safe place.

Rotate the black plastic reverse bulb socket 1/4 turn counterclockwise and pull it straight out of the housing.

Push in a new number 7440 bulb in to the socket.

Re-insert the socket in to the housing and rotate it 1/4 turn clockwise to secure it in place.

Re-insert the three pop rivet fasteners and push in their center pieces to secure them in place.

To test the new tail light bulbs, have an assistant step on the brake pedal, activate the hazard signals and place the transmission in reverse.

For more, check out my other 2014-2018 Mazda Mazda6 DIY Repair & Maintenance Guides.